The present invention is directed to an explosive powder charge operated fastening element setting device with one part of the device forming a housing, another part forming a handle with the handle being displaceable with respect to the housing against the force of a damping unit. In addition, a fastening element guide is mounted in the housing for movement opposite to the setting direction of the setting device against the biasing action of a spring force.
An explosive powder charge operated setting device is disclosed in U.S. Pat. No. 2,731,636, and includes a housing with a fastening element guide displaceable relative to the housing opposite to the setting direction and against the force of a spring. An additional spring is positioned between a part of the device acting as a handle and the housing and the spring serves for damping the recoil acting on the setting device operator when a fastening element is driven. Accordingly, the spring acts as a damping device, however, it has several shortcomings with regard to its operation.
In particular, the damping effect of a spring, as mentioned above, is adequate only at a low spring rate. A low spring rate requires a large space requirement, so that a device equipped with such a damping unit is unwieldy. The utilization of a higher spring rate reduces the damping effect, so that a high proportion of the undesirable recoil forces continue to act on the operator. Moreover, the restoring velocity of such a known spring is so high that concussive forces acting on the operator occur during the reset operation.